package com.cloud.shopping.tool;

import javax.servlet.http.HttpServletRequest;

/**
 * @author John.zhang
 * @version Id: IpUtils, v 1.0 2021/1/6 14:24 ZhiYong Exp $
 * IP获取
 */
public class IpUtils {

    /**
     * 获取用户真实IP地址，不使用request.getRemoteAddr()的原因是有可能用户使用了代理软件方式避免真实IP地址,
     * 如果通过了多级反向代理的话，X-Forwarded-For的值并不止一个，而是一串IP值
     *
     * @return ip
     */
    public static String getIpAddr(HttpServletRequest request) {
        String ip = request.getHeader("x-forwarded-for");
        String defaultStr = "unknown";
        if (ip != null && ip.length() != 0 && !defaultStr.equalsIgnoreCase(ip)) {
            // 多次反向代理后会有多个ip值，第一个ip才是真实ip
            String comma = ",";
            if(ip.contains(comma)){
                ip = ip.split(",")[0];
            }
        }
        if (ip == null || ip.length() == 0 || defaultStr.equalsIgnoreCase(ip)) {
            ip = request.getHeader("Proxy-Client-IP");
        }
        if (ip == null || ip.length() == 0 || defaultStr.equalsIgnoreCase(ip)) {
            ip = request.getHeader("WL-Proxy-Client-IP");
        }
        if (ip == null || ip.length() == 0 || defaultStr.equalsIgnoreCase(ip)) {
            ip = request.getHeader("HTTP_CLIENT_IP");
        }
        if (ip == null || ip.length() == 0 || defaultStr.equalsIgnoreCase(ip)) {
            ip = request.getHeader("HTTP_X_FORWARDED_FOR");
        }
        if (ip == null || ip.length() == 0 || defaultStr.equalsIgnoreCase(ip)) {
            ip = request.getHeader("X-Real-IP");
        }
        if (ip == null || ip.length() == 0 || defaultStr.equalsIgnoreCase(ip)) {
            ip = request.getRemoteAddr();
        }
        return ip;
    }

}
